Hi, I hope someone can help diagnose this problem.

Just recently my GT380 triple has started cutting out.

It cuts out after about 10 - 15 miles running from cold. When it cuts, it's usually accelerating at medium revs.

There's no warning, it just cuts stone dead on ALL three cylinders. At the moment it cuts, the gear indicator light and all other electrics go dim & fade right out.

If I flick the engine kill switch OFF at this point (cutting the power feed to the coils) the gear indicator & electrics up brightly again.

But the engine will NOT restart until the ignition has been OFF for a couple of minutes. Then it will fire normally, like nothing happened, but it will cut out dead again after a couple of miles.

Does this sound like a dead short or break in the coil low-tension windings, or the power feed to the coils?

It ONLY does it after 15 minutes or so of riding. After it's begun cutting out, it continues to cut every couple of miles.

Connections to the coil look solid, and it runs great right until it cuts stone dead.

The ignition is points, battery, 3x coils.

New plug caps (NGK non-resistor) and new plugs (B8EVX), ran fine for 250 miles before it started cutting out.

I originally thought it was a dying battery. But I have just fitted a brand new, fully-charged 9Ah, 80amp battery so I don't think that's the problem.

I don't think it's the charging system, as it's been happily running total loss for the past 4 years. Until a couple of weeks ago, I could do 75+ miles on the 7Ah, 40A battery between charges. The new battery is higher rated but it still dies.

Thanks in advance for any input / help ....

could it be the rectifier? i used to have a Honda MT5 (i was only 16) and i had a problem similar to this and it turned out to be the rectifier, it was getting rather hot and then not working?
i found this out when i took off the tank and saw that it had melted big time! it kept blowing bulbs as well (so i put 24v bulbs in :freak3: oh the joys of innocent youth) it was prob this that melted the rectifier in reality :D

That sounds to me like one or more of the coils are on their way out, as they are getting warm, the insulation is failing and putting a big drain on the battery.

Agreed - it's almost certainly a coil with the insulation breaking down and creating a dead short...

Easy enough to fix provided you can get a coil, of course.

SB

Thanks guys :)

I wondered if the coils' internal insulation had failed and was just dumping all the battery juice straight to earth.

I have a set of used coils coming this week ...

Get over to the forums on the Suzuki Owners Club at http://www.suzukiownersclub.co.uk/ They're nearly as helpful as those kind folk on SN .... :D

Dave - owner of GT250B (all in bits) and AP50 (mainly together ...)

Thanks Dave -- already have done so ;)

The coil is the chief suspect, although a good look over the wiring diagram has given me a couple of other places to investigate too :)

BB I had a similar problem on a KMX200, i swopped EVERYTHING over(was lucky to have a donor bike) with out joy...was the ruddy kill switch in the end.

Let us know the outcome anyway.

Update -- I seem to have found the remedy.

Going thru the wiring in the headlamp body, I found that that the female half of the connector block for the kill switch had gone a bit deformed, as if some heat had been applied to it.

My guess is that the connector contact for the main power feed for the coils was poor, creating a resistance which was giving intermittent connection and also heating the plastic body of the connector block.

A good clean with some switch cleaner and a fiddle with the brass connectors appears to have sorted it ...

Thanks for all the input, and a gold star to Brybusa :)